1. Field of the Invention
The present invention relates to methods and systems for identifying and addressing service providers in packet data networks from whom mobile terminals can obtain application level services.
2. Description of the Prior Art
Voice over IP (VoIP) networks having a network architecture of a cellular network connected to a packet data network map addresses from the numerically based addressing of the cellular mobile networks to the alphanumeric addressing mechanism such as universal resource locators (URLs) of packet data networks such as IP networks. Such systems are specified under H.323 and include gatekeepers.
Gatekeeper discovery mechanisms have been proposed in order for mobile terminals to have access to application level network services such as VoIP. With one of these mechanisms a mobile terminal will actively communicate with the servers in the packet data network from which available services may be obtained by using multicast probing to access the servers in the network. With the other mechanism, the mobile terminals will monitor communications in the network to identify periodic announcements from servers in the packet data network from which application level services are available and, in response to an announcement from server(s) that services are available, the mobile terminal will register with the available server(s). The foregoing mechanisms by which mobile terminals may obtain the location of application level services provided by servers in a packet data network increase the transmissions through the packet data network in proportion to the number of available servers providing services to the mobile terminals and can reach an undesirable level, especially when the communications are over mobile packet data networks which have limited bandwidth.
The service location protocol (SLP) defines agents in a network which may be discovered by use of dynamic host configuration protocol (DHCP). When a terminal powers up and executes DHCP procedures, it may request location of a SLP agent, such as a service agent, by utilizing option 78 in the DHCP discovery message.
FIG. 1 illustrates the architecture of the general packet radio system (GPRS) 10. The GPRS 10 has entities which support radio transmission of packet data transmissions. A plurality of mobile terminals 12, which may be connected to a computer 14, communicate via radio communications 16 to a base station 18 which includes a transmitter 20 and a controller 22. Each base station is associated with a mobile switching center (MSC) and visiting location register (VLR) 24 with which the mobile terminals 12 register when activated in the network. The base station 18 and the MSC and VLR 24 may be in accordance with the GSM (global system for mobile communications) network specifications. The GPRS 10 has an infrastructure 26 which includes a plurality of serving general packet radio systems support nodes (SGSN) 28 which perform the functions of authenticating the mobile terminal when the user wishes to connect to the GPRS network and also act as the nodes responsible for setting up GPRS sessions for carrying such traffic as IP. The GPRS infrastructure 26 further includes a backbone network 30 which provides wireline interconnections to the various entities in the GPRS infrastructure 26. The GPRS infrastructure 26 further includes at least one gateway general packet radio system support node (GGSN) 32 which provides gateway functions to external data networks 34 which may be without limitation the internet or an X.25 data network from which services may be accessed by the mobile terminals 12. Firewalls 36 may be provided between the GGSN 32 and the external networks 34. Additionally, at least one gateway 37 provides gateway services between the GPRS infrastructure 26 and other GPRS operators 38 through a firewall 40. The GPRS 10 further includes an SS7 network 42 of known design which provides support for the establishment of communications between different entities in the network such as without limitation between different mobile terminals 12. A home location register (HLR) 44 provides functionality of the type performed by the HLR in the GSM system. Additionally, other data networks 46, such as the internet are connected through a GGSN 32 to a plurality of corporate entities via a router 48 to a local area network including a corporate server 50.
The GPRS 10 may include. at least one mobile service providing server 52 which may be, without limitation, at least one host application level service entity, such as a call processing server (CPS), a streaming server, or an application server. A CPS performs the functions of setting up, controlling and tearing down of VOIP calls among other functions. A streaming server performs the functional of providing movies, audio or other playback of information on demand from a packet data network. An application server performs the function of running functions that either the mobile terminals 12 cannot support or runs functions for the mobile server.
The GPRS 10 suffers from the deficiencies discussed above regarding discovery and registration by the mobile terminals with the at least one mobile service providing server 52 to obtain application level services for the mobile terminals. The active or passive discovery technique by which the mobile terminals 12 obtain application level services from at least one mobile service providing server 52 burdens and overloads the GPRS 10 with undesirable communications especially in view of the limited bandwidth available.
The present invention is a network and a method of providing mobile terminals in a packet data network with an address of at least one storage device which stores the address of at least one service providing entity, such as a server from which application services are obtainable, by the mobile terminals. In accordance with the invention, a directory storage, which may be implemented as an advertisement server, provides addresses to the mobile terminals in the network of at least one mobile service providing server from which diverse types of application level services may be obtained by the mobile terminals. The advertisement server is a repository of addresses of servers in the network with which the plurality of mobile terminals may register and obtain application level servers therefrom. Once a mobile terminal obtains an address of at least one mobile service providing server from the directory storage for use by a mobile terminal, the mobile terminal communicates with each mobile service providing server to further discover specific application services that are available to the mobile terminal. The network may operate under specified access control rules so that at least one service from the mobile service providing servers is made available to the mobile terminal based upon specified conditions such as, but not limited to, the identity of the mobile terminal, preferences of services which the mobile terminal desires to procure from the mobile service providing servers, any roaming protocol which is to be used, or prevailing network conditions including, e.g. load on the individual server(s), or any other type of conditions which are desired to be used as a basis to control access. The directory storage may be implemented in accordance with the Service Location Protocol (SLP) as a service agent. However, discovery of such an agent when DHCP is not available and multicast-based approaches are not desirable is addressed by the present invention in which the address of the directory storage is provided to the mobile terminal upon its network registration. However, the invention is not limited to SLP and/or dynamic host control protocol.
The mobile terminals, upon activation, register with the network which may be performed by either of two service registration processes. The address of the directory storage is required before application level service registration can be effected by either of the two service registration processes. The registration process may be comprised of a first part in which the mobile terminal registers with the network for connectivity and transport services in accordance with well-known cellular network or other known network registration principles and, in a second part, registers to obtain application level services which is hereinafter referred to as service registration which may be without limitation VoIP or any other application level service. One type of service registration process is referred to as the distinct service registration process in which the network supplies the address of the directory storage to the terminal and another type of registration process is referred to as an integrated service registration process during which the network itself communicates with the mobile terminal after successful network registration and performs registration with available servers on behalf of the terminal. With the integrated service registration process, the network returns to the mobile terminal a list of registered services and the addresses of the services from which the services are obtained which addresses may be URLs of the individual mobile service providing servers in the network. Thereafter, the mobile terminal stores the list of available services which are obtainable by addressing mobile service providing servers with the URLs or other addresses of the mobile service providing server entities in the network. The mobile terminal uses wireless packet data communications to communicate with the mobile service providing servers which are accessible by the addresses obtained via one of the registration processes described earlier.
The registration procedure with the network may be in accordance with the GPRS Attach procedure which is known and the service registration procedure may be in accordance with an H.323 registration message if the mobile service providing server in question is a VoIP server with H.323 protocol support.
The network is required to provide the address of the directory storage. When the integrated service registration process is utilized, the network has to perform the service registration on behalf of the mobile terminal once the network registration by the mobile terminal is successful. In response to a network registration request by the terminal, which may be a GPRS Attach procedure, the network may perform service registration with servers accessible to the terminal and return addresses of those servers with suitable attributes (such as their capabilities, e.g., whether the VoIP server supports multi-party conferencing) which the mobile terminal can use when services are to be obtained. The service registration procedure may precede a GPRS session establishment procedure which is established using a PDP context establishment message (a PDP context activation allows a mobile terminal to send and receive packet data in a GPRS network) so that service registration messages may be carried over established PDP sessions. A PDP session must be established before service registration messages may be carried over the PDP session. However, if the distinct service registration process is utilized, the network only has to return the address of the directory storage.
The function of the directory storage is to provide the addresses of available mobile service providing servers to the mobile terminals. In the distinct service registration process, the directory storage may process the service registration request from the mobile terminal and apply access control rules based upon varying conditions such as, terminal preference, user alias, the network state in terms of its utilization, server state in terms of server utilization, etc., and provide to the mobile terminal only those addresses which are allowed to be accessed by the mobile terminal. The directory storage may obtain the processing criteria used to complete a selective service registration requested from other entities in the network. Furthermore, the directory storage, in addition to providing addresses of the mobile service providing servers, may also return service attributes which constitute capability and function, such as, can the address server support VoIP, call forwarding, multiparty calls, etc, of the mobile service providing server.
The invention in one form is a network. A plurality of mobile terminals transmit and receive information transmitted through the network. At least one storage is coupled to the network which is accessible by the plurality of mobile terminals that provides services to the mobile terminals. A directory storage is coupled to the plurality of mobile terminals which stores addresses of the at least one storage and which provides in response to a communication at least one address of the at least one storage to at least one of the mobile terminals with which at least one of the mobile terminals may communicate to obtain service therefrom. The network may comprise a packet data network. The network may comprise a packet data network and a cellular network which are coupled together with a gateway. The mobile terminals may be within the cellular network and the directory storage and the at least one storage may have addresses in the packet data network. The network comprises at least one entity which stores a profile of each mobile terminal and the plurality of terminals, upon activation in the network, register with the network and the directory storage provides an address of each storage providing a service stored in the profile of the at least one entity from which the registered terminal may access services. The at least one entity may be a home location register. The network provides each of the plurality of mobile terminals an address of the directory storage upon activation and registration of each of the mobile terminals with the network. Each mobile terminal upon activation registers with the network and in response to mobile terminal registration, the network registers each activated mobile terminal with the directory storage and the directory storage returns an identification of any available registered services to each mobile terminal which stores the identification of registered services for future access. The directory storage applies access control rules to control access of the at least one mobile terminal to the at least one storage.
The invention is also a method of providing a plurality of mobile terminals with services. The method is practiced in a network having a plurality of mobile terminals which transmit and receive information transmitted through the network and at least one storage which is accessible by the plurality of mobile terminals and which provides services to the mobile terminals. A directory storage is coupled to the plurality of mobile terminals which stores addresses of the at least one storage from which the mobile terminals may obtain services. In response to a communication in the network, an address of at least one storage is provided to at least one mobile terminal from which the at least one mobile terminal may obtain services. The at least one mobile sends a communication to the address of the at least one storage requesting that the addressed storage provide services to the at least one terminal sending the communication. The network may comprise a packet data network. The network may comprise a packet data network and a cellular network which are coupled together with a gateway. The mobile terminals may be within the cellular network and the directory storage and the at least one storage may have addresses in the packet data network. The network comprises at least one entity which stores a profile of each terminal and the plurality of terminals, upon activation in the network, register with the network and the directory storage provides an address of each storage providing a service stored in the profile of the at least one entity from which the registered terminal may access services. The at least one entity may be a home location register. The network provides each of the plurality of mobile terminals an address of the directory storage upon activation and registration of each of the mobile terminals with the network. Each mobile terminal upon activation registers with the network and in response to mobile terminal registration, the network registers each activated mobile terminal with the directory storage and the directory storage returns an identification of any available registered services to each mobile terminal which stores the identification of registered services for future access. The directory storage applies access control rules to control access of the at least one mobile terminal to the at least one storage.